im 83 kg, i use talon 40 with 111 with sails 7.0, 7,5, 8,0 gaastra gtx race (i should switch to race sails). with 7.0 its awesome, with 7.5 quite good, with 8.0 its a little bit small, i use 36 with 111 down to 6 with no cam sails (hope to get some smaller sail also ).

talons are very fast fins with right size and hardly spin out, and if it occurs very easy to recover in a blink. its a very very good fin, best that i use. (dont have to much experience with others by the way i use drake, deboichet SL1)

on the other hand Last month i was on 40, a friend was on 38 with both is111, both on 7.0 freerace he experience some spin outs when hardly push the board, but i have 1 spin out in 4 hours. ??

Best combo imho: (im not an expert by the way %50 gybe success yet )

34 up to 6.3 with 97is (dont have smaller board i guess i should buy one also but use talons with 97 several times)
36 up to 6.7 - 97is
38 up to 7.2 - 97is
40 up to 7.8 - 107is
42 up to 8.5 - 107is

never use it in a bigger size, and i wonder its performance is the same?? any one who use it for a size like 50-52